<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>update</title>
<style type="text/css">
	body {background-color: white; color: black; font-family:sans-serif; font-size:medium;}
	a:link {color: #3300ff;}
	a:visited {color: #663399;}
	a:hover {color:#0099ff;}
	a:active {color: #0066cc;}
	a.button {text-decoration:none;}
	
	table.nav  {background-color: #dbddff;}
	table.body {margin-top:2ex; margin-bottom:2ex;}
	table.programlistingindent {margin-left:32px;}
	
	img { margin-bottom:0px; margin-top:0px;}
	tt {margin-left:0.5em; margin-right:0.5em; font-weight:lighter;}
	
	p {margin-top:0ex;}
	p.synopsis {margin-left:32px;}
	p.programlistingindent {margin-left:32px;}
	p.citetitle {margin-left:2em;}
	
	ul ul {list-style-type:square;}
	ul li p {margin-top:0ex; margin-bottom:.5ex; padding:0}
	ol li p {margin-top:0ex; margin-bottom:.5ex; padding:0}
	
	h1.reftitle {color:#a90000;}
	h1.reftitle {font-size:3.7ex; margin-top:0; margin-bottom:0; font-weight:bold}
	h1.title {color:black; font-size:4ex; margin-top:1ex; font-weight:bold}
	h2.title {color:#bd0000; margin-top:1ex; margin-bottom:.9ex; font-weight:bold; font-size:3ex}
	h3.title {color:#bd0000; margin-top:1ex; margin-bottom:.9ex; font-weight:bold; font-size:2.5ex}
	h4.title {color:#bd0000; margin-top:1ex; margin-bottom:.9ex; font-weight:bold; font-size:2ex}
	h2 {color:#bd0000; margin-top:1ex; margin-bottom:.9ex; font-weight:bold; font-size:2.5ex}
	h3 {color:#bd0000; margin-top:1ex; margin-bottom:.9ex; font-weight:bold; font-size:2ex} 
	
	pre.programlisting {margin-left:32px;}
	pre.synopsis {margin-left:32px;}
	
	
	.categorytitle {margin-top:8px; padding-top:0px;}
	.categorylist {background-color: #e1e6f2;}
 	</style>
</head>
<body>
<a name="top_of_page"></a><p style="font-size:1px;"></p>
<h1 class="reftitle">update</h1>
<h2>Purpose</h2>
<p>Updates the internal state using the state-update equation</p>
<h2>Syntax</h2>
<pre class="synopsis">system.update(u)</pre>
<pre class="synopsis">xn = system.update(u)</pre>
<pre class="synopsis">[xn, y] = system.update(u)</pre>
<h2>Description</h2>
<p></p> 
    This function evaluates the system's state-update equation and
    updates the internal state of the system.<br><br>

    By calling <tt>system.update(u)</tt> this function updates the
    internal state of <tt>system</tt> by evaluating the state-update
    equation. The updated state can then be retrieved by calling <tt>x
    = system.getStates()</tt>.<br><br>

    By calling <tt>[xn, y] = system.update(u)</tt> this function also
    returns the updated state as the first output, and the result of
    the output equation as the second output. Note that the internal
    system's state is still updated as described above. 
  <h2>Input Arguments</h2>
<table cellspacing="0" class="body" cellpadding="4" border="0" width="100%">
<colgroup>
<col width="31%">
<col width="69%">
</colgroup>
<tbody><tr valign="top">
<td><tt>u</tt></td>
<td>
<p></p>Vector of system's inputs<p>
	    		Class: <tt>double</tt></p>
</td>
</tr></tbody>
</table>
<h2>Output Arguments</h2>
<table cellspacing="0" class="body" cellpadding="4" border="0" width="100%">
<colgroup>
<col width="31%">
<col width="69%">
</colgroup>
<tbody>
<tr valign="top">
<td><tt>xn</tt></td>
<td>
<p></p>Updated state vector<p>
	    		Class: <tt>double</tt></p>
</td>
</tr>
<tr valign="top">
<td><tt>y</tt></td>
<td>
<p></p>Vector of outputs<p>
	    		Class: <tt>double</tt></p>
</td>
</tr>
</tbody>
</table>
<h2>Example(s)</h2>
<h3>Example 
				1</h3>Define a 1D LTI system <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update1.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update1.png">, <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update2.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update2.png">
      <pre class="programlisting">sys = LTISystem('A', 0.9, 'B', 1, 'C', 0.5)</pre>
<pre class="programlisting">LTISystem with 1 state, 1 input, 1 output
</pre>Set the system's internal state to <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update3.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update3.png">.<pre class="programlisting">sys.initialize(1);</pre>
<pre class="programlisting"></pre>Update the system's state using <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update4.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update4.png">.<pre class="programlisting">sys.update(0.2);</pre>
<pre class="programlisting"></pre>Retrieve the internal state (should be equal to <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update5.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update5.png">).<pre class="programlisting">sys.getStates()</pre>
<pre class="programlisting">
ans =

                       1.1

</pre>Update the system's state using <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update6.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update6.png">.<pre class="programlisting">sys.update(0)</pre>
<pre class="programlisting">
ans =

                      0.99

</pre>Retrieve the internal state (should be equal to <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update7.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update7.png">).<pre class="programlisting">sys.getStates()</pre>
<pre class="programlisting">
ans =

                      0.99

</pre>Update the internal state using <img src="../../../../../fig/mpt/modules/ui/@LTISystem/update8.png" alt="../../../../../fig/mpt/modules/ui/@LTISystem/update8.png"> and retrieve
    the updated state and the associated output<pre class="programlisting">[xn, y] = sys.update(-1)</pre>
<pre class="programlisting">
xn =

                    -0.109


y =

                     0.495

</pre>
<p></p>
<table class="nav" summary="Navigation aid" border="0" width="100%" cellpadding="0" cellspacing="0"><tr valign="top">
<td align="left" width="20">
<a href="reachableset.html" class="button">&#9664;</a>  </td>
<td align="left">reachableset</td>
<td>  </td>
<td align="right">ltisystem</td>
<td align="right" width="20"><a href="ltisystem.html" class="button">&#9654;</a></td>
</tr></table>
<br><p>©  <b>2003-2013</b>     Michal Kvasnica: STU Bratislava,    <a href="mailto:michal.kvasnica@stuba.sk">michal.kvasnica@stuba.sk</a></p>
</body>
</html>
